Random chip of the day: spi resistor chip

Folks,

So continuing my mission to fill the mailing list with things you probably already know. Today's random component spam is the AD8400 digitally controlled potentiometer chip.

The cool thing about digitally controlled pots is that you can use them from embedded procs, ards or whatever, to get a pot controlled by your code. If you have a use for this, you might already be familiar with the ad5204, which I think is pimped by sparkfun. Or possibly the MCP41xx and MCP42xx series.

So why do you like the AD8400? It goes down to 1k ranges with 256 steps in the range. With a wiper resistance of 50 ohms, so you can get down to around 56 ohms on the low end.

These are around $3 a pop from digikey, and I am about to order a small handful of them in about an hour if anyone wants a couple give me a yell in the next few minutes.

j

This is actually quite a neat component to know about. I had never really thought about something like this existing.

I’ve used them before… on great example was on my CNC driver electronics… I use them to set the current limiting on the stepper driver board. Easier to do with software… and the software can change it when necessary… like for rapid movements, etc.

Bill

I’ve used them before… one great example was on my CNC driver electronics… I use them to set the current limiting on the stepper driver board. Easier to do with software… and the software can change it when necessary… like for rapid movements, etc.

Bill

Digipots are the flip side of the DAC. I probably have a good number of these around Judas. I don’t remember what part# off the top of my head, but if you tell me what you need I can see if I have it. Bring your BOM with you tomorrow night. I’ll try to bring all my components down with me. If you need anything I have, it’s yours. I’m getting to have a lot of common SMT stuff.
-D

Dave,

Except the displays I have already ordered everything I need. But given the great joy I find in comparing the various types and colors of smoke I can generate from different electronic components, I might very well be taking you up on your kind offer at some point in the near future.

j